Oolong is a traditional Formosan (now Taiwan) tea which is somewhere between a green and a black tea with a 10-70% oxidation range. An extremely popular brand, it has neither the rosy sweet aroma of black tea nor the strident grassy notes that typify green tea. When brewed, it is strong, bitter but with a sweet after taste. The Chinese O-liong te means black dragon tea and the oolong leaves before roasting are rolled and bruised to break open cell walls and stimulate enzymatic activity. Roasting then removes unwanted odours, reduces astringency and makes this a tea which is gentle on the stomach. The polyphenols in oolong is supposedly known for controlling obesity by activating the enzyme that breaks down triglycerides and so it is popular with weight watchers.